In this special edition of DNews, intrepid explorer Trace Dominguez is joined by our resident space guru Ian O'Neill to investigate the methods by which mathematical equations could help us find life on other planets.

Two mathematical equations in particular are critical in this line of inquiry. The Drake Equation is the more famous of the two. Created by astronomer Frank Drake, the equation breaks down the entire Milky Way galaxy into numbers to estimate how many alien civilizations could be out there in our neighborhood galaxy.

Drake's equation was developed in the early 1960s, just after we realized that our newfangled radio antennae might be able to pick up alien communications. The equation takes into account a long list of variables: average rate of star formation; the fraction of those stars with planets; the fraction of those planets which could support life....

Drake added still more qualifiers, since we're looking for communicative alien civilizations -- those that have been around long enough to develop the necessary technology. Clearly, we're dealing with a lot of unknowns, but the idea is to provide a range on the number of planets that could have life.

Very recently, scientists have come up with another equation that comes at the problem from another direction. The Scharf-Cronin equation uses planetary chemistry to calculate the odds of life forming in a particular plot of cosmic real estate in the first place.

The math gets complicated indeed, but the upshot is that Scharf-Cronin equation can give a rough estimate of the likelihood that an origin-of-life event will occur on any given planet. The process of turning non-living chemicals into a functioning biology is called abiogenesis, and we're learning more about this phenomenon every day.

That's the real beauty of science's two-equation approach to the alien life conundrum. With every new space mission and terrestrial experiment, we gather more data to plug into the these two equations. The new data, in turn, help us figure out where to point our radio dishes and aim our space probes.